// electric.c -- calculates electric bill
#include <stdio.h>
#define RATE1 0.13230		// rate for first 360 kwh
#define RATE2 0.15040		// rate for next 108 kwh
#define RATE3 0.30025		// rate for next 252 kwh
#define RATE4 0.34025		// rate for over 720 kwh
#define BREAK1 360.0		// first breakpoint for rates
#define BREAK2 468.0		// second breakpoint for rates
#define BREAK3 720.0		// third breakpoint for rates
#define BASE1	(RATE1 * BREAK1)
// cost for 360 kwh
#define BASE2	(BASE1 + (RATE2 * (BREAK2 - BREAK1)))
// cost for 468 kwh
#define BASE3	(BASE1 + BASE2 + (RATE3 * (BREAK3 - BREAK2)))
// cost for 720 kwh
int main(void)
{
	double kwh;				//  kilowatt-hours used
	double bill;			//	charges

	printf("Please enter the kwh used.\n");
	scanf("%lf", &kwh);		// %lf for type double
	if (kwh <= BREAK1)
		bill = RATE1 * kwh;
	else if (kwh <= BREAK2)	// kwh between 360 and 468
		bill = BASE1 + (RATE2 * (kwh - BREAK1));
	else if (kwh <= BREAK3)	// kwh between 468 and 720
		bill = BASE2 + (RATE3 * (kwh - BREAK2));
	else					// kwh above 680
		bill = BASE3 + (RATE4 * (kwh - BREAK3));
	printf("The charge of %.1f kwh is $%1.2f.\n", kwh, bill);

	return 0;
}